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  <head>
    <meta charset="UTF-8" />
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    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      var sum = 100
      console.log(sum > 100) //false
      console.log(sum >= 100) //true

      // == 比较两边 值 是否相等，不管数据类型
      // === 比较两边 值和数据类型 是否相等
      var a = 1
      var b = '1'
      console.log(a == b) //true
      console.log(a === b) //false

      console.log(true == 1) //true
      console.log(true === 1) //false

      console.log('' == 0) //true
      console.log('' === 0) //false

      console.log(null == 0) //false
      console.log(undefined == 0) //false

      // != 不等于 两边 值 是否不等
      // !== 不等于 两边 值和数据类型 是否不等
      var a = 1
      var b = '1'
      console.log(a != b) //false
      console.log(a !== b) //trie
    </script>
  </body>
</html>
